diff options
Diffstat (limited to 'src/math/roundf.c')
| -rw-r--r-- | src/math/roundf.c | 61 |
1 files changed, 20 insertions, 41 deletions
diff --git a/src/math/roundf.c b/src/math/roundf.c index 662a454b..c6b27797 100644 --- a/src/math/roundf.c +++ b/src/math/roundf.c @@ -1,48 +1,27 @@ -/* origin: FreeBSD /usr/src/lib/msun/src/s_roundf.c */ -/*- - * Copyright (c) 2003, Steven G. Kargl - * All rights reserved. - * - * Redistribution and use in source and binary forms, with or without - * modification, are permitted provided that the following conditions - * are met: - * 1. Redistributions of source code must retain the above copyright - * notice unmodified, this list of conditions, and the following - * disclaimer. - * 2. Redistributions in binary form must reproduce the above copyright - * notice, this list of conditions and the following disclaimer in the - * documentation and/or other materials provided with the distribution. - * - * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR - * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES - * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. - * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, - * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT - * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, - * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY - * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT - * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF - * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. - */ - -#include <math.h> +#include "libm.h" float roundf(float x) { - float t; + union {float f; uint32_t i;} u = {x}; + int e = u.i >> 23 & 0xff; + float_t y; - if (!isfinite(x)) + if (e >= 0x7f+23) return x; - - if (x >= 0.0) { - t = floorf(x); - if (t - x <= -0.5) - t += 1.0; - return t; - } else { - t = floorf(-x); - if (t + x <= -0.5) - t += 1.0; - return -t; + if (u.i >> 31) + x = -x; + if (e < 0x7f-1) { + FORCE_EVAL(x + 0x1p23f); + return 0*u.f; } + y = (float)(x + 0x1p23f) - 0x1p23f - x; + if (y > 0.5f) + y = y + x - 1; + else if (y <= -0.5f) + y = y + x + 1; + else + y = y + x; + if (u.i >> 31) + y = -y; + return y; } |